Background: Developmental dysplasia of the hip (DDH) is one of the most important and challenging conditions inthe field of pediatric orthopedics; if not diagnosed and treated in time, it would lead to remarkable morbidity. Methodsof treatment based on the patient’s age can vary. The aim of this study is to compare the outcomes of Salter osteotomysurgery in two groups of patients under and over three years old.Methods: In this retrospective study, medical records of patients who had undergone innominate Salter osteotomy,within the past ten years, due to non-pathological DDH were collected. Mean follow up of all patients is 70.28 months(min=25, max=118).Results: seventy patients were selected including 85 operated hips. Radiological satisfaction based on modifiedSeverin score system rate was 86% and 85% for lower three years old group and second group, respectively. In clinicalassessment, it was found that results in 82% of the patients under 3 years old and 82.9% of patients older than threeyears old were satisfactory. There was no statistically significant difference between the two groups based on ModifiedMacKay criterion.Conclusion: Results in both groups of patients under and over 3 years old were found satisfactory. Difference inpatient satisfaction rates based on clinical and radiological outcomes was not statistically significant between thetwo groups. It should also be noted that complications such as redislocation and deep wound infection would causepoor clinical and radiological outcomes.